Introduction: Ectopic posterior pituitary (EPP) is a malformation of the hypothalamic-pituitary region presented as a spectrum from isolated growth hormone deficiency (GHD) to multiple pituitary hormone deficiencies (MPHD). Our goal was to establish whether the FAST1.2 protocol, which combines FAST1 protocol with 3D-T2DRIVE images, could identify the pituitary stalk (PS) and the regional anatomy more accurately. Methods: A retrospective study of 36 individuals with EPP and hypopituitarism, and a control group of 78 individuals with eutopic posterior pituitary. All individuals were submitted to FAST1.2. The position and size of the pituitary lobes were described, and the presence/absence of the PS was confirmed. Results: FAST1 identified the PS in 19% of individuals with EPP, while FAST1.2 identified the PS in 67% (p<0.001). In the FAST1.2 protocol, the PS was visible in all control individuals. All EPP patients with isolated GHD had visible PS in FAST1.2, while only 58,6% of MPHD cases had visible PS. The size of the anterior lobe and the anteroposterior length of the posterior pituitary were smaller in the EPP group vs controls (p<0.001). We noticed a reduced anterior pituitary lobe in both diameters in MPHD patients (p<0.05). Six patients acquired new pituitary hormone deficiencies not recognized at the time of MRI, in this group only one patient had a PS not visible in FAST1.2. Discussion/Conclusion: The FAST1.2 protocol could prevent the misdiagnosis of idiopathic GHD in patients with short stature and could also be important in the progression to MPHD. The PS could be considered a predictor of hypopituitarism, but its use as an isolated indicator for the progression to MPHD is not recommended. Our results reinforce the use of the size of the anterior lobe as a predictor of hypopituitarism and a possible predictor of the degree of pituitary insufficiency FAST1.2 protocol could be used as an alternative to gadolinium administration, as a cheaper and faster method, while eliminating the potential risks associated with the administration of contrast media.

Objective: Test if the MRI FAST1.2 protocol can detect extra-pituitary midline structural brain abnormalities in patients with ectopic posterior pituitary (EPP), and highlighting their radiologicallaboratory correlations. Subjects and methods: Cross-sectional study of patients with EPP and control group. All individuals were submitted to FAST1.2, which combines the FAST1 protocol developed by our group with 3D T2DRIVE imaging. Results: We evaluated 36 individuals with EPP and 78 as control group. Pituitary stalk (PS) was identified in 7/36 patients in EPP group by FAST1, and in 24/36 patients in FAST1.2 (p < 0.001). FAST1 failed to detect PS in one individual in the control group, while the FAST1.2 defined the PS in all individuals. In EPP group, eleven had interhypothalamic adhesion (IHA), three septo-optic dysplasia, and one cerebellar malformation. We didn't observe higher frequency of panhypopituitarism or developmental delay in patients with IHA. In control group, three had pars intermedia cysts, one hydrocephalus, and one hypothalamic hamartoma. Conclusion: FAST1.2 allows confident recognition of midline structural abnormalities, including the pituitary stalk and IHA, thereby making MRI acquisition faster and with no need for contrast administration. IHA could be associated with defects in neuronal migration, as occur in patients with EPP, with no clinical significance.

Background Ectopic posterior pituitary (EPP) is a malformation of the hypothalamic-pituitary region. Our goal was to describe midline structural brain abnormalities in patients with EPP using a dedicated protocol (FAST1.2 protocol) of magnetic resonance imaging (MRI) to evaluate the hypothalamus and pituitary gland, highlighting their clinical-laboratory correlations. Methods A cross-sectional study of patients diagnosed with EPP, and a control group. All individuals were submitted to a dedicated MRI protocol called FAST1.2, which combines the FAST1 protocol developed by our group with 3D T2DRIVE imaging. Results We evaluated 36 individuals with EPP and 78 individuals as a control group. One patient had two posterior pituitary lobes, one inside the sella turcica and the other along the pituitary stalk; in five patients, the EPP was along the pituitary stalk; in 28 the EPP was at the infundibular recess of the third ventricle, and in two the EPP was hypothalamic. In the EPP group, eleven individuals had interhypothalamic adhesion (IHA), three septo-optic dysplasia, one a cerebellar malformation, and one a pineal cyst. We did not observe a higher frequency of severe hormonal deficiency or developmental delay in patients with IHA. In the control group, eleven patients had a pineal cyst, three pars intermedia cysts, one hydrocephalus, and one hypothalamic hamartoma. Conclusion FAST1.2 acquisition allows confident recognition of regional anatomy and recognition of midline structural abnormalities on T2DRIVE, particularly including the pituitary stalk and IHA, thereby making MRI acquisition faster with no need for intravenous contrast administration. We suggest that IHA could be associated with defects in neuronal migration, as might occur in patients with EPP.